Different types of known modulators for shaping the cornea of an eye have been proposed for refractive surgery. Widely used is a modulator from photoabltable polymer that is placed in the optical path of a transportation system of a laser beam. This type of modulator, which has the shape of a spherical or of a toroidal lens is used for the correction of the usual refractive irregularities, like myopia or astigmatism. A modulator remote from the eye has the disadvantage, however, of correcting only simple and predefined refractive irregularities of the eye.
It is also known to cover of the corneal surface, just before irradiation, with a solution of collagen which solidifies immediatelly after its placement over the cornea. The collagen typically covers the irregularities of the corneal surface. The collagen through the surface forms a relatively smooth external surface. This smooth surface is xe2x80x9cprojectedxe2x80x9d finally on the cornea due to the same ablation rate of collagen and the cornea. While this method permits the smoothing of the cornea, it cannot give any prediction for the final shape of the corneal surface especially when the cornea has geometric irregularities of large size compared to the size of the optical zone, for example, irregular astigmatism, scares and dystrophy of the cornea.
Therefore, there exists the need for modulators that can be used in order to correct the surface irregularities of the cornea and at the same time change the shape of the cornea in a way that good optical performance is achieved.
A device includes a molding lens and elements for controlling the temperature of the mold. The molding lens includes an external surface having a concave shape to correspond to the desired shape of the cornea. The device can shape a substance such as hydrogel on the surface of the cornea in the process of developing a photoablatable lenticular modulator for laser irradiation. The temperature of the molding lens can be controlled in various ways. Such ways include circulation of a liquid in the molding lens, supplying an air stream having a controllable temperature on an internal or external surface of the molding lens and contacting the surface of the mold with a heating element.